@Bastien Montagne (mont29): I think users would expect the addon to import the image as well as set up the appropriate material/texture/image/nodetree for them.
In case of BI, the addon also sets use_alpha (along with other settings) for the image [and this option "Use Alpha" is also grouped under "Material Settings" in the addon UI].

OK, see the point, but think you took the issue by the wrong end then. :)
What you probably want to do here is to change how Cycles mat is generated to match behavior of BI mat generation (that is, remove the Diffuse & Transparent, and Emission & Transparent shading options, and automatically use them when 'use_transparency' import option is set).

nodetree creation stays the same, but transparent BSDF (along the other needed nodes) is now added when Import Option "Use Alpha" is checked

use_alpha (along alpha_mode, use_fields) is correctly set for the image now -- calling existing "set_image_options(image)" for this -- formerly ignored when using cycles

[ note: version 1 of this patch was against an older revision, so didnt notice "Use Alpha" was already exposed in the UI already for cycles as well... -- just to clear up my previous comment ]

Philipp Oeser (lichtwerk) retitled this revision from Import Images As Planes: set "use_alpha" for images in cycles as well to Import Images As Planes: set image options ("use_alpha", ...) for images in cycles as well.Aug 23 2015, 5:11 PM

Bastien Montagne (mont29) retitled this revision from Import Images As Planes: set image options ("use_alpha", ...) for images in cycles as well to Import Images As Planes: Automatically generate a transparent material nodes system when enabling 'use_alpha', for Cycles..Aug 23 2015, 5:38 PM